1. Technical Field
The present invention relates to a liquid ejecting head including a piezoelectric element which causes a change in pressure in a pressure-generating chamber communicating with a nozzle opening and which has a piezoelectric layer and an electrode that applies a voltage to the piezoelectric layer, and also relates to a liquid ejecting apparatus.
2. Related Art
Piezoelectric elements used for liquid ejecting heads, for example, have a structure in which a piezoelectric layer composed of a piezoelectric material having an electromechanical conversion function, such as a crystallized dielectric material, is interposed between two electrodes. Such piezoelectric elements are mounted, for example, as actuator devices having a flexural vibration mode, in liquid ejecting heads. A typical example of liquid ejecting heads is an ink jet recording head in which a part of a pressure-generating chamber is made of a vibration plate, the pressure-generating chamber communicating with a nozzle opening that ejects ink droplets, and by deforming the vibration plate by a piezoelectric element, ink in the pressure-generating chamber is pressed so as to be ejected as ink droplets from the nozzle opening.
The piezoelectric material used for the piezoelectric layer (piezoelectric ceramic) constituting such a piezoelectric element is required to have high piezoelectricity, and a typical example thereof is lead zirconate titanate (PZT) (refer to JP-A-2001-223404).
However, from the standpoint of environmental concerns, a piezoelectric material having a reduced content of lead has been desired. Examples of a lead-free piezoelectric material include BiFeO3 having a perovskite structure represented by ABO3. When a BiFeO3-based piezoelectric material is used, a problem may occur in which bismuth contained in the piezoelectric material diffuses into a vibration plate, thus adversely affecting the vibration plate composed of a material containing silicon. In addition, such a problem occurs not only in ink jet recording heads that eject ink, but also in liquid ejecting heads that eject droplets other than ink.